Net cathode



Sept. 30,, I ERGANG 1,776,787

NET GATHODE Filfid July 1927 Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE ADOLF ERGANG, or MAGDEBURG, GERMANY, assienon, BYM Esnn nssisimnnrs, iro

THE RAGUHN-IANHALTER MnTALLLocnnnnI M. 1 H1, or ansn'nn, r/nmmnr,

GERMANY.

Application filed July 7, 1927, Serial No.

gauze is effected by bending the wires, not all the points of the surface of the net'are in contact with the diaphragm above the same, whereby theelectrolytic effect of the surface of the net becomes irregular, said surface becoming even ineffective at certain points. I am also aware that metallic cathode plates have ben made of sheet metal with elongated openings therethrough, and also with circular perforations. Cathode 7 plates of such type have fiat faces which are objectionable in that they buckle or bend and do not insure an effective contact. My invention provides an eifective contact and the grid cathode, constructed as shown, maintains maximum rigidity, as the spaces through the plate or grid are bounded by portions and give effective contacts and greater area of surface, as the transverse and the longitudinal portions of the grid are circular incross section.

This invention has for its object, to avoid these inconveniences"connected with the commonlyused wire-nets.

The longitudinal and transverse solid portion between the holes are rounded on the upper surface so that'the contacting surface between the cathode-grid and a diaphragm becomes as small as possible as, owing to the junction of the solid portions with curved surfaces, grooves are produced at the-points of intersection. The diaphragm therefore rests on the plane or flat surface of the grid.

This construction of the grid presents further advantage in use that the resistance conditions as a cathode are favorable as the solid portions extend in both longitudinal and transverse directions and participate at the same time in the flowing through the grid of the current, so that the electric resistance NET GATHODE V r 204,017, and in Germany June 23, 1926.

is the same in all portions of the grid, the

longitudinal bars and the transverse bars participat ng uniformly in the passage of the current. Asat no points, variationyof the resistance occurs, no burning {of the grid: can

take place and as-the contact-surface for the diaphragm isperfectly plane, this diaphragm -1s1n uniform contact throughout. a

' The production of thegridfrom a plate comparison with'wire An embodiment of the invention is illustrated,by' way of examplefin the accompanying drawings, in which V Fig. 1 shows the net in cross section. Fig.2 is a top plan vieW of Fig. '1. Fig. 3 shows the punch in a plan view seen from below.

Fig. i is a side elevation of the punch. The circular cross section a in Fig. 1 corresponds to the cross section of a wire-gauze. When the height of the grid is the same in the sheet-metal-net as in the wire net the surface I) in Fig. 1 in the stamped net is further available as current conducting cross section. The cross section of the bars may however be further increased in downward direction by means of the surface 0 in Fig. 1, the useful top-surface being not altered thereby so that,

siderably greater passage-cross section for the current is obtained than with Wires.

The diaphragm d is in contact with each i bar along a line so that almost the entire curved surface of the bar is free for the electrolytic-efiect.

The improved net may be made from a plate of sheet-metal with the aid of a punch which, when punching the hole, produces simultaneously the curvature of the bar.

The punch is shown in Figs. 3 andt.

It consists essentially of a square shaft 9' with an extension h of smaller cross section and slightly enlarged towards the point. The extension h merges into the shaft 9 gradually by a chamfer is designed to produce the curvature of the bar at the depression of the punch.

The cathodes made from sheet-metal pre-'- sent the further advantage that they can be fixed in the bath in a simple manner by fold- Ving over the outer edges.

I claim:

5 1. A. grid or lattice having longitudinal and transverse inte ral members for use as a cathode, said'mem rs being spaced to encompass rectangular openings, such members 7 having semi-circular portions on one side ex- 10 'cept at their grooves or points of juncture, the si es being parallel beyond the semi-circular portions, the faces opposite said semi-circular portions being plane surfaces.

2. A grid cathode comprising integral 10ngitudinal and transverse members, a portion thereof being convex in cross section, said convex portions being groined at their junctions, the opposite portions of said members having flat surfaces which are on the same plane with each other.

3. A grid-shaped cathode for electrolytic baths, consisting of longitudinal and transverse connected bar-like 'meinbers,--the upper portion of which are convexedly vcurved or rounded and located on the same plane, the sides thereof joining opposite faces which are on the same plane, and provide a flat surface for engagement with a, diaphragm.

"so In testimony whereof I alfiximy signature.

ADOLF ERGANG. 

